Mandrel for abrasive and polishing tools



H. F. STEMPEL, JR.

MANDREL FOR ABRASIVE AND POLISHING TOOLS.

APPLICATION man JAN. 13. 1921.

1,417,584. P te e May 30, 1922.

- lIVI/E/VTUR WITNESS 4 HGRMAN 7". 6 'rMPez,

ATTORNEYS HERMAN FREDERICK srnmrnn, an, or roar-M DISON, IOWA.

nrANnanL non ABRASIVE AND ronrsnine TOOLS.

To all who-met men concern: I i

Be it known that I, HE MAN FREDERICK STEMPEL, Jr; a citizen of the United States,

My invention relates generally to man drels for abrasing and polishing tools and particularly, although not necessarily, to

dental mandrels'for grinding and polishing wheels and discs.

A purpose of my invention is the provision of a mandrel which securelyholds grinding and polishing wheels and'discs against slippage relative to the mandrel and in such manner as to prevent concentration of stress around the edge'of the mandrel thus preventing the wheels from cutting out or breaking at the center and thereby materially prolonging the life of the wheels. Furthermore, my invention provides means for yieldingly supporting the wheels, and one which eliminates theemployment of face pins.

I will describe one form of mandrel embodying my invention and will then point out the novel features thereof in claims.

In the accompanyingdrawings:

Figure 1' is a view showing one form of mandrel embodying my invention and having applied thereto a conventional form of grinding or polishing wheel. I p

Figure 2 is a vertical sectional View of a portion of the mandrel and the wheel shown in Figure l.

Figure 3 is an enlarged detail perspective viewof the arbor of the mandrel shown in Figures 1 and 2.

' Figure 4 is a detailed perspective view of the clamping 'screwcomprised in the man drel.

Figure 5 is a perspective view'ol the cushioning sleeve shown inFigures 1 and 2.

Figure 6 is a similar view of the cushioning washer-shown in Figures 1 and 2. I

' Similar reference characters refer to similar parts in each of the several views.

Referring specifically to the drawings and particularly to Figures 2 and 3, my invention in its present embodiment comprises an arbor'A having its tool carrying end bored, as indicated at 15, and interiorly threaded to receive a clamping screw S. The extreme end of the arbor A is formed with a head 16 of disc formation with its periphery formed Specification oflLetters Patent. Patentd B [ay Application filed January 13, 1921. Serial No. 436,995.

at intervals with recesses 16. The clamping screw S comprises a threaded shank 17 which appreciably exceeds in length thatiof the bore 15 so as to accommodate the grinding wheel. as will be understood. The screw S also includes a head 18 which is slotted to receive a screw driver in the application. and removal of the tool to and from the arbor;

Embracing the tool end of the arborisa cushioningsleeve K preferably formed-of rubber and preferably of the form shown in the drawings. This cushioning sleeve Kis adapted to be vulcanized onto the arbor a l so as to completely house the head 16 but to maintainthe'entrance end of the bore15 stood that the periphery of the head 16 can be roughened in any suitable manner so long as the interlocking action between lts peripheryand the sleeve iselfected. c

' A washer W preferably formed of rubber is mounted on the shank 17 of the screw S in the manner shown in Figure 2 so as to cushion the screw head 18 with respect to the grinding of the latter by the former.

Wheel and to thus prevent injury open for the reception of the clamping screw I S. In the applied-position of the sleeve K} With a grinding wheel designated at ,G associated with the mandrel as shownin Fig ures l. and 2, it will be clear that the screw S serves to secure the-wheel upon the arbon,

In this position the wheel is' clamped between the screw head 18 and the arbor head I 16 but the opposite sides of the wheel a0- tually contact with the cushioning sleeve K and the washer W so that it may besaid that the wheel is'yieldingly secured upon the mandrel.

As the sleeve is vulcanized on the arbor A and locked against relative.

rotation by means of the head 16, it will be clear that in the applied T position of. the

screw, thelwheel is fixedly secured against rotation with respect to "themarbor. The diameter of the outer end of the cushioning sleeve K is such as to cover a relatively large area of the corresponding side of the wheel, the actual diameter of the sleeve K is by virtue. of this sleeve that concentraexceeding the diameter of the head 16. It

the cushioning sleeve K that the grinding wheels are protected against being cut out at their center which is the main objection to the use of mandrels heretofore constructed. By the elimination of this undue wear at the axis of the grinding wheel, it is obvious that the life of the wheel is materially prolonged and that the possi' bility of the wheel breaking due to excessive strains at its axis, is eliminated. The cushioning sleeve because of its elasticity also serves to absorb sudden shocks which frequently occur during the grinding oaeration, and which prevents the transmission ofthese shocks to the grinding wheel.

Although I have herein'shown and de scribed only one form of mandrel embody-- ing my invention, it is to be understood that various changes and modifications may be .made herein without departing from the spirit of the invention and the spirit and scope of the appended claims.

WVhat I claim is:

1; A mandrel comprising, in combination, an arbor bored at one of its ends, a head of irregular outline formed on the bored end of the arbor, a cushioning sleeve embracing the bored end of the arbor and said head, a clamping screw threadedly fitted within the bore of the arbor, and a resilient washer mounted on the shank of said screw.

:2. A mandrel conrprising, an arbor, a. metal head formed on one end of the arbor and having radial recesses at intervals in its periphery, and a rubber Sleeve encasing the head and having portions thereof disposed in said recesses, the sleeve and the head end of the arbor being axially bored and adapted to receive a member for securing the .tool on the mandrel.

3. A mandrel comprising, an arbor, a metal head formed on one end of the arbor and having radial recesses at intervals in. its periphery, a rubber sleeve encasing the head and having portions thereof disposed in said recesses, and removable means extending into the sleeve and arbor for removably securing a grinding disc or wheel to the arbor.

head and having portions thereof disposed in said recesses, the head end of the arbor being bored axially and threaded, and a screw extending into the sleeve and engaging the threaded portion of the arbor for clamp-- ing a disc or wheel against the sleeve.

5. A mandrel comprising anarbor, a metallic head of irregular outline formed at one end of the arbor, a resilient sleeve'of conical form fixedly secured to the arbor and embracing the head, and means extend ing through the sleeve and into the arbor for securing a tool to the arbor and against said sleeve.

6. A mandrel comprising an arbor, a metal head formed on one end of the arbor having radially extending recesses formed at intervals in the periphery thereof, a coneshaped rubber sleeve fixedly secured to the arbor and embracing saidhead in such manner that portions of the sleeve repose within said recesses, and means extending into the sleeve engagingthe arbor for se curing a tool against the sleeve.

7. A mandrel comprising an arbor, a metallic head formed on one end of the arbor and having radially extending recesses formed on the periphery thereof, a cone shaped rubber sleeve vulcanized on the arbor and arranged in such manner that its base projects from one end of the arbor to constitute the face of the tool-end of the arbor, said sleeve embracing saidhead and having portions thereof disposed in said recesses to effect the interlocking of the sleeve with the arbor, and means extending into tlie'sleeve and engagingthe'arbor for detachably securinga tool against the base end of the sleeve.

8. A mandrel comprising an arbor, a c0nesliaped rubber sleeve embracing the arbor at one end with its base end projecting from the end of the arbor, means for locking the sleeve against'movement on the arbor, and means for detachably securing a tool against the projectingend of the sleeve.

9. A mandrel comprising. an arbor, a cone-shaped rubber sleeve fixedly secured to one end of the arbor in such manner that the base of the cone projects from one end Of'the arbor, and a clamping screw threadedly fitted within the arbor for securing a tool against the base-end of the sleeve.

HERMAN FREDERICK STEMPEL, Jr. 

